Wilson Holliday Audulus, £6.99/$9.99

Audulus is an iOS port of the modular soft-synth for Mac of the same name. It’s well designed interface also users to build polyphonic synths by combining the 27 built-in modules.

Right now the app is missing a few key features we’d like to see, such as presets, Audio Copy/Paste and Virtual MIDI but we’re promised all these features are coming soon - along with Audiobus support.

Fingerlab DM1 v3, £2.49/$3.99

Compatibility: iPad (requires iOS 5.1 or later)

DM1 has proved to be one of the more popular groove tools available for iOS. Version 3 adds the ability to import your own samples - which was the last of the key features we found to be missing when we reviewed v1 last year (Audio Copy and MIDI in were added in version 2).

RobStar Square Loops, 69p/$0.99

In round-up 73 we highlighted RobStar’s aesthetically pleasing groovebox Square Beats. Well Square Loops is essentially a stripped down, entry-level version of that app. It's based on the same engine but packs less features and is available for a cheaper price.